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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: blackdiesel on December 22, 2014, 07:11:00 PM

Title: Measuring bullet diameter?
Post by: blackdiesel on December 22, 2014, 07:11:00 PM
I'm about to get a digital caliper, will it be enough to get exact diameter for bullets?  Is there a better more precise instrument that do not cost a lot?
Title: Re: Measuring bullet diameter?
Post by: Bwalton on December 22, 2014, 07:17:51 PM
I'm about to get a digital caliper, will it be enough to get exact diameter for bullets?  Is there a better more precise instrument that do not cost a lot?
you can use a micrometer thats what I use
Title: Re: Measuring bullet diameter?
Post by: dogwood on December 22, 2014, 07:44:56 PM
Second Micrometer, they are much better for measuring round things accurately
Title: Re: Measuring bullet diameter?
Post by: Tofazfou on December 22, 2014, 09:07:02 PM
Spend the money and get a GOOD MIC

MICROMETER

Way more accurate and measures down to a more FINITE number
Title: Re: Measuring bullet diameter?
Post by: Rescue35 on December 22, 2014, 10:32:45 PM
You can pick up an OK mic at sears for $20.
Title: Re: Measuring bullet diameter?
Post by: blackdiesel on December 22, 2014, 11:44:36 PM
Thanks for your replies....
Title: Re: Measuring bullet diameter?
Post by: KnifeMaker on December 23, 2014, 05:26:39 AM
This is going to be hard to believe, but Harbor Freight is now carrying an electronic digital mic. for about 35 buck. with carbide anvils.. Now the shocker. It is well made, and Very accurate!
Model number-  Item# 68305 Pittsburgh SAE & Metric  Digital Micrometer

Measures down to .00000

Hard to believe I know!

Knife
Title: Re: Measuring bullet diameter?
Post by: Bill G on December 23, 2014, 07:24:03 AM
The rule for measuring is that your insturment needs to have a resolution of 1/2 the smallest reading.

If you want to take measurements of .0001, then your insturment must read .00005. 

If the horrible frieght mics measure a joe block or guage pin accurately and repeat, then they are worth every penny and you are getting an awesome deal. If they only repeat within the .001 then you have mics for measuring .002.

 It really boils down to just how small you think is small.  As a note, If you are trying to measure things accurately in the .00000 range, don't touch it very long and don't hold the mic.  Many materials will swell from the heat of your hand.  Aluminum is a complete waste of time to try and measure at those high resolutions (IMO).  I haven't tried lead, I'll have to do that. 

Bill